How to specify multiple enum values for EnumValueOptions inside a Protobuf file

Question

I want to pass on multiple enum value options as per below inside a proto file,
but i find compilations errors, while specifying values as per (types) = [5,6] inside below code block :

    extend google.protobuf.EnumValueOptions {
      optional string name = 50001;
      repeated int32 types = 50002; 
    }

    enum FileDefinitionSubType {
        UNKNOWN = 0;
        MAIN = 1 [
          (name) = "main",
          (types) = [5,6]                   // Compilation error in this line 
        ];
      } here

Can someone suggest how to fix this problem. Below is a sample enum that i have in my java code, which i want to replicate in proto file.

enum CarType {
      UNKNOWN = 0;
      NEW = 1 ("new", [MARUTI_ALTO, FORD_ECOSPORT]);
      OLD = 2 ("old", [MARUTI_800, FORD_FIGO]);
      MIDAGE = 3 ("midAge", []);
}

enum CarModel {
      UNKNOWN = 0;
      MARUTI_800 = 1;
      MARUTI_ALTO = 2;
      FORD_ECOSPORT = 3;
      FORD_FIGO = 4;
}

I already tried giving passing different set of values, but nothing worked.

Answer 1

According to language specification:

To set multiple values when an option field is repeated, use multiple option declarations with the name of that field.

Which means this:

enum FileDefinitionSubType {
    UNKNOWN = 0;
    MAIN = 1 [
      (name) = "main",
      (types) = 5,
      (types) = 6
    ];
  }

The separate values will get collected into the repeated list, as can be verified by protoc --decode:

$ protoc -otest.pb test.proto
$ protoc --decode=google.protobuf.FileDescriptorSet google/protobuf/descriptor.proto < test.pb
...
  enum_type {
    name: "FileDefinitionSubType"
    ...
    value {
      name: "MAIN"
      number: 1
      options {
        50001: "main"
        50002: 1
        50002: 2
      }
    }
  }
...

Alternatively you can put all of your options inside a submessage, and use the "protocol buffers text format" to give the values:

message MyOptions {
    optional string name = 1;
    repeated int32 types = 2; 
}

extend google.protobuf.EnumValueOptions {
    optional MyOptions myopt = 50001;
}

enum MyEnum
{
    MyValue = 1 [(myopt) = {name: "main", types: [1,2]}];
}